Polycarbonate is an engineering plastic widely used in the plastics industry.
Polycarbonate can have a glass transition temperature (Tg) of about 150° C. by virtue of a bulky molecular structure, such as bisphenol A, and thus can exhibit high thermal resistance. Also, a carbonyl group in a carbonate group has high rotational mobility and thus can impart flexibility and stiffness to polycarbonate. In addition, polycarbonate is an amorphous polymer having superior transparency and can exhibit excellent properties in terms of impact resistance and compatibility with other resins.
However, polycarbonate has poor flowability and is often used in the form of alloys with various resins to complement workability and post-processability.
Among such alloys, a polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS) alloy can have excellent properties in terms of durability, thermal resistance, and impact resistance and is used in various fields such as electrical/electronic products, optical devices, automotive components, construction materials, medical instruments, food containers, and other real-world materials. For example, PC/ABS alloys can be easily used as a large molded article emitting lots of heat, such as automotive components, computer housings, or office equipment.
Some molded articles may be subjected to deposition after injection molding, as needed. In deposition on plastic materials, a deposition process is generally performed after surface coating of an injection molded product.
Recently, direct deposition methods have been developed which omit surface coating of a molded article prior to deposition to overcome environmental problems. In such methods, surface properties of an injection molded article become major factors influencing deposition.
Conventionally, a molding method such as rapid heat cycle molding (RHCM) has been used to adjust gloss of a surface of an injection molded article. However, this method has a limitation in productivity due to long injection molding time. In another method, the amount of a rubber polymer in a thermoplastic resin composition can be reduced to obtain a molded article with a high gloss surface. This method, however, has a problem of deterioration in properties such as impact strength due to decreased rubber amount.
Therefore, there is a need for a thermoplastic resin composition which has excellent gloss and heat stability while maintaining inherent properties of the resin composition.